A quarter coin is half in value of a half-dollar coin. Therefore, two quarters makes up each half dollar coin.
Now, we know that Jessie has 14 half-dollar coins, but she needs quarters to do her laundry. Thus, if each half-dollar coin gives two quarters then 14 half-dollar coins will give
quarters.
Thus, if Jessie trades all her 14 half-dollar coins for quarters, she will have 28 quarters for her laundry.